Riveting press for commutator assemblies



y 1950 J. w. DOLAN 2,516,681

RIVETING PRESS FOR COMMUTATOR ASSEMBLIES Filed Nov. 12, 1946 4 Sheets-Sheet 1 INVENTOR. JOSEPH W. DOLHN.

ATTORNEYS- July 25, 1950 J. w. DOLA'N 2,516,681

RIVETING PRESS FOR COMMUTATOR ASSEMBLIES Filed Nov. 12, 1946 4 Sheets-Sheet 2 I INVENTOR. bsEPH W. Domm.

110.7.- BY W ATTORN EYS.

July 25, 1950 .1. w. DOLAN .RIVETING PRESS FOR COMMUTATOR ASSEMBLIES 4 Sheeis Sheat 3 Filed Nov. 12, 1946 INVENTOR. DaLnN. BY

ATTORNEYS- illlll lul r Patented July 25, 1950 RIVETING PRESS FOR COMlWUTATOR ASSEMBLIES Joseph W. Dolan, Dayton, Ohio, assignor, by mesne assignments, to The Third National Bank and Trust Company of Dayton, Ohio, Dayton, Ohio, 2. national bank of the United States Application November 12, 1946, Serial No. 709,343

22 Claims.

My invention relates to presses for completing the assembly and clinching over the retaining sleeve in commutators.

A commutator, as will be more fully described consists of an assembly of longitudinally extending bars with intervening strips of insulating material such as sheeted mica, assembled about a retaining ring and a sleeve which is part of another retaining ring, the sleeve extending through the first noted retaining ring and being flanged outwardly to clinch the rings into position. The two rings have a V shaped like formation in cross section, the outer flange of the V shape entering a groove formed in each of the commutator bars and hence extending concentrically about the assembly of bars.

The task to be performed by my novel mechanism is to bring the commutator bars to a perfect alignment lengthwise, squeeze the assembly together tightly circumferentially while forcing them to lengthwise position, and then while the whole is gripped in this fashion forcing the sleeve of the mounting to flange outwardly against the retaining ring through which it projects.

commutator assemblies are first prepared with the sleeve and ring portions in engagement and tacked to holdthem in assembly. The assembly is then heated, and thereupon is ready for operation by my mechanism.

It is desirable to perform this operation in a single stroke of die in a suitable press and to present the commutator assemblies on a rotating table to the die, which moves step by step, i. e., indexes around, permitting a constant supply of the assemblies to the die. It is one of the objectives of my invention to so provide, and this requires the production of a die which will perform all of the required steps at a single rapid operation and automatically. Such a die is an objective of my invention.

Ancillary objects are to provide a die assembly which is quickly and readily adjustable to take various sizes of commutators, and in which the amount of pressure applied to the parts being worked upon can be adjusted without varying the pressure of the press ram itself.

A further objective is to provide for the various objects noted in a relatively small and compact mechanism, aside from the press itself, which is inexpensive, and simple to disassemble and reassemble as well as to adjust.

,I will describe a construction and arrangement of parts constituting an example of my invention, same being intended as illustrative of the principles involved. The novelty to which my insented to the coining die.

2 vention is directed I will set forth in the claims that follow the specification.

In the drawings:

Figure l is a top plan view of the coining head, or die member.

Figure 2 is a side elevation thereof.

Figure 3 is a bottom plan view thereof.

Figure 4 is a section taken on the line 4-4 of Figure 1, i. e., it shows two sections on different planes connected at the center line, the central portion being in common and being shownin elevation.

Figure 5 is a detail vertical section through a commutator assembly.

Figure 6 is a perspective of one of the inner group of spring retaining studs.

Figure 7 is a perspective of. one of the con-. stricting jaw elements.

Figure 8 is a section alike to Figure 4 showing the parts of the die member in position of initial engagement with a commutator assembly.

Figure 9 is a like view to Figure 8 showing the second stage of the operation of the die with the inner group of springs compressed. Figure 10 is a third like section showing the position of the parts at the completion of the upsetting, or coining, operation just before lifting of the die member.

Figure 11 is a section like Figure 5showing the completed and coined commutator assembly.

Figure 12 is a bottom plan view, partly broken away showing the squeezing jaw assembly.

Figure 131s a diagrammatic plan view on a small scale of the indexing table on which the commutator assemblies are Referring first to Figures 1, 2, 3 and i the coin ing head or die member is formed of a ring shaped body I having mounted thereon an adjustable control ring 2 for the outer set of springs of the die and within this outer control ring is an inner control ring 3 for the inner set of springs of the die. The outer ring is controlled in its position by having teeth 2a formed around 'the lower edge thereof to be engaged by pinions la on the main body which pinions may be rotated by the operator, any one of them serving to adjust the position of the outer ring. The inner ring 3 has peripheral teeth 3a thereon which are engaged by pinions 2b located by studs 20 (see Figures 1 and 2) on the flat ring 4 which mounts the outer spring retaining studs.

Referring to Figure 4, it will be noted that ring 2 is mounted antifrictionally on the outside of the main body as indicated by the balls- 5. I

mounted and pre The ring is internally threaded as at 6 where it engages the fiat ring 4. Since the ring 4 has mounted on it the spring retaining pins of the outer series (to be described below) it cannot rotate, thence rotating the ring 2 causes the pin retaining ring to move up and down thus adjusting the position of the pins, and as we shall see of the outer series of springs. Also (Fig. 4) it will be noted that the inner control ring 3 is threaded internally and engages the apertured plate 1, that, as we shall note, is bolted to the plunger ID of the press and to the housing 8 for the inner set of spring retaining pins of the device. The plate I being thus secured to the ram Hl, rotation of the ring 3 by the pinions 212 will cause the ring 3 to be raised or lowered depending on the direction of rotation imparted to the pinions 2b. This ring, as will be noted, abuts against the tops of the inner series of spring retaining pins, and thus the adjustment of the ring adjusts the compression of the inner set of springs,

Referring now to Figures 4, 8, 9, and the device shown at 8 was referred to above as the housing for the inner set of spring elements. This housing 8 is integral with the main body I as is most clearly seen in Figures 4 and 10. The bolts which mount this inner body or housing 8 on the plate 1 are shown at 9 (see Figure 1 and Figure 4). The plate I is secured to the ram in of the press by means of a heavy bolt H which projects upwardly into the ram.

In a series of holes in the portion 8 are mounted springs 12 constituting the inner series, in an annular arrangement. The springs are retained lengthwise by means of a series of pins (3 (Fig. 6) which have notched heads 14 the notches being arranged to form shoulders for engagement against plate I.

There is a second inner body portion 15 slidably held within the bore of the body I. This inner body portion has holes 16 in its margin into which the pins or studs i3 find a sliding seat. The springs I2 engage the margin of the body portion 15.

The body portion I has a series of holes 16a therein, in which are located springs I? which bear on a lower sliding plate 18 of the device. Spring control pins l9 for this outer series of springs pass through the springs, and enter holes in the plate (8 wherein said pins can slide. The heads of the pins as indicated at 20, are engaged at the top by the adjustable ring 4, which ring is secured to the pins by means of studs 2| which are threaded into the heads of the pins.

As so arranged, the compression of the springs l'l against the lower sliding plate i8 is controlled by the orbital position of the ring 2 on the main body. The compression of the springs I2 on the inner sliding body 15 is controlled by the position of the ring 3 (adjusted by pinions 2b). Both the plate l8 and the body l5 are free, against the compression of the springs, to rise within the outer body.

In order to hold the lower plate or annulus IS in position on the body a retaining ring 22 is provided which is bolted about the margin of the outer body at the bottom and holds plate It against moving downwardly by virtue of engagement with a shoulder 23 about the top of the said plate.

The parts so far described, except the plate 18 and the retaining ring therefor, are a permanent part of the die. The remainder of the structure is modified to suit commutators of different sizes, same being held in place essentially by the retainin ring and the plate I8. The exception to this fact is the central plunger of the die which as illustrated has a head 24', and a threaded portion 25 above the head which is screwed into the inner body portion 8. The head is formed with a bevelled seat 26 which, if the die is compressed far enough will seat at the conical seat 21 in the inner sliding plate ['5. The central plunger is guided in a stripper slide block 28 and terminates in a tip 29 which is shaped to enter the sleeve portion of the commutator and has a filleted shoulder 30 which in the final operation of the die swedges outwardly the end of the commutator sleeve.

The stripper block has a body 28 which slides within the sliding body portion i5. It has springs 3| in a circular series, controlled in position by pins 32 held in a separate ring 33, and engaging in holes in the block at their lower ends. The springs 3| tend to hold the block in lower position, and the first operation of the die is to compress these springs.

The block has a sleeve portion 34 in which the central plunger is guided, as has been noted, which sleeve portion terminates in a circular shoulder 35 which presses down on the upper collar of the commutator assembly, at the same time that the plunger enters the sleeve portion of the commutator.

Referring to Figures 5 and 11, will be found a commutator assembly as placed into the press and as completed. The assembly consists of commutaor bars 36 in a circumferential assembly and havin at each end a V-shaped groove. In each groove is seated a mica or other insulation material ring 31, a sleeve of like material 38 is located internally of the assembly, and the bars are themselves separated by mica sheets. The assembly of the bars and insulation is held together by two members, in the present example, a metal sleeve 39 terminating in a ring of V-shaped cross section as at 39c, and a ring 46 of V-shaped cross section placed over it at the top, the rings seating also in the V-shaped grooves in the ends of the assembly. Usually the sleeve where it projects through the ring 40 is tacked during assembly to hold the parts together. The machine will force the bars lengthwise against the supporting base, force the two collar portions together, squeeze the bars tightly together and while the bars are held tightly lengthwise and squeezed together will swedge over the projecting end of the sleeve. The difference between Figure 5 and Figure 11 is shown in the expanding or swedging at 4! of the sleeve 39. This holds the parts together in their compressed position.

The table of the machine has a properly shaped retainer for each assembly, as illustrated most completely in Figure 4, consisting here of a block 42 with a recess at the top to receive the assembly,

and with a central spring plunger 43 which enters the sleeve of the assembly from below and is displaced so far as required by the central plunger tip 29 as soon as the die comes into operation. When the die operation has been completed the last thing to take place is for the springs 3! to expand and push down on the stripper block 28, the shoulder 35 thus pushing the assembled commutator out of the die.

The lower sliding member or annulus 18 has mounted thereon a series of plates 44, S-shaped in cross section, held in place by bolts 45 let into the portion I8, and also by locating pins 46. The

lilie upper ends of these plates act as abutments in the squeezing operation. The bolts 45 also mount on the end of the portion [8, a retaining ring 4'! which ring holds in place the squeezing jaw plates. In Figure 7 is a perspective of one of these plates and Figure 12 is an end view of the assembly. These jaw plates have body portions 48 with outwardly projecting shoulders 49 which rest on the retaining ring 41. The jaw plates also have spring pockets 50 at each sidewall in which are mounted springs 51 which act to spread the jaws to a normal expanded position.

The jaws are circular in horizontal section and form a ring when assembled together. Grooves m in the inner faces of the jaws engage over an inner retaining ring 52, and the upper portion of the shoulders 49 hold an outer retaining ring 53. The upper ends of the jaws engage the upper ends of the S-shaped plates 44, and the jaws are here bevelled off as indicated at 54. The commutator bar engaging portion of the jaws is the lower curved inner face portion 55 of each, and the ring 52 engages the ends of the commutator bars of the commutator.

The upper ends of the jaw plates engage the lower face of the stripper block 28. The block 28,

the central plunger and the jaw assembly, are the portions of the die which are replaced to take care of different sizes of commutators. As noted these parts can be thrust into place and held by the retaining ring ill in the lower open portion of the main body.

Referring now to the operation of the device: in Figure 4 the parts of the die are shown in up-- per position before an operation has begun. The indexing table of the press is provided with suitable mounting blocks for the commutator to to be worked upon and presents the commutators one at a time to a position beneath the press head on which is mounted the die.

The first stage of the operation, as shown'in Figure 8, is for the central plunger 29 to enter the commutator and the shoulder at the bottom of the stripper block to engage the upper ring on the commutator assembly, and shortly thereafter the ring 52 contacts the ends of the commutator bars provided ring 52a is not present-as will be more fully described later. The springs 3i will then compress as further downward movement continues. forces down the apertured plate 1, the inner sliding body 55 will rise against the adjusted compression of the spring I 2. This is because the stripper block will have bottomed at the top of its recess in the body I5 and the springs l2 will thus begin to compress. As shown in Figure 9 a space will develop between the sliding body It and the sliding annulus l8. At this point the assembly of bars will be very strongly pressed down against the supporting block on the table correcting any error of lengthwise adjustment by reason of the engagement of the commutator bars by the ring 52 and seating the V-shaped cross section rings more firmly in place by virtue of the engagement of the shoulder 35 on the end of the stripper block.

The contact of ring 52 and the commutator bars is indicated at 51 in Figure 9 and is the basic contact of the system. These bars are supported from below on the mounting block, and the result is an effort to move the squeezing jaws 48 upwardly. The jaws engage the top of the S-shaped plates 44 which will wedge the jaws together be cause of their bevelled tips. The result is to put As the press head I pressure on the springs l1 to-compressthem-by forcing upwardly on the lower sliding annulus or plate I8. The jaws thus are brought to a position of squeezing the commutator bars together due to the contraction of the ring of squeezing jaws. v The portion [8 will rise somewhatas indicated by the space 56 in Figure 10 (compare with Figure 8) which shows the finish of this operation.

As this point, as shown in Figure 10, the final pressure applied to the v ring is the resistance of the springs l 2. Thus the ring is pressed home when the squeeze and lengthwise pressure has fully lined up the V grooves for the V rings. There the fillet 36 above the tip of the central plunger will come down strongly on the projectin end of the sleeve portion of the commutator assembly and expand it outwardly and downward- 1y against the upper V-shaped cross section ring as of the assembly while the assembly is under compression. This locks permanently the assembly with respect to its lengthwise or axial and its circumferential relationship.

As the die rises with lifting of the press plunger, the several parts release seriatim, with the final result that the shoulder 35 pushes the completed coined assembly out of the die.

The operation is fast, and while the sequence described is not exactly essential it provides the results in an adequate manner. Because the commutator is heated before being placed on the indexing table there will be some compression of the insulation pieces thereby compensating for slight errors in the positioning of the end V-grooves in the commutator bars. The simultaneous lengthwise force and circumferential force applied tends also to compensate for any such errors. It is desirable, however, to allow for the small variations in thickness of copper supply in grooving the bars in automatic machines so that the rings at the ends of the assembly do not tend to hold the bars against being tightly squeezed around the central sleeve of the assembly. Small margins of error are not, however, important for the reasons above described.

The amount of pressure, except for the final expanding of the sleeve, is adjustable by preliminarily adjusting the compression of the two sets of springs for the two sliding portions of the die.

As distinguished from coining operations on commutators which apply a squeeze, followed by a staking as two operations accomplished at different stages, requiring two operations, the

present device performs the work in a single op eration of the die, and furthermore applies lengthwise compression of the assembly while the contraction of the same is taking place. To accommodate the coining operation to an indexing table as a means of supply, requires that a rapid operation take place and that this be done at one operation. The adjustment rendering the pressures controllable other than by the adjust ment of the press plunger force, is highly de sirable in accommodating different sized assemblies which require diiferent pressures. The fact thatthe adjustable feature is all supplied by parts which fit up into the bottom'of the die body, being held by a single retaining ring, is important from the point of view of make ready in factory operations.

Instead of springs and retaining pins it is apparent that from the broader aspect of my invention, plugs of rubber or rings of rubber could be substituted.

Additionally, if it is not desirable to contact the commutator bars with the ring 52, this ring (while it may be retained) is prevented from striking the bars by means of an abutment, say a ring 52a (Fig. 4) which abuts the ends of the jaws 48 and forms the basic contact for the die.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A press for commutator assemblies comprising an indexing table having thereon a series of supports for commutator assemblies and movable to present said supports seriatim to a die, a press plunger and a die mounted on said plunge said die having means contained therein for (a) pressing the commutator bars of the assembly lengthwise, (b) pressing the V ring of the assembly axially thereof, squeezing the as sembly of bars circumferentially intermediate their ends and, while said recited means are in operation, (d) spreading outwardly the terminus of the mounting sleeve oi the assembly into tight engagement with the said V ring, said means arranged to act on the commutator assembly upon a single operation of the press plunger, said contained means comprising a plurality of slidable elements having compressible elements opposing their movement on work engaging movement of said die.

2. A press for commutator assemblies comprising an indexing table having thereon a series of supports for commutator assemblies and movable to present said supports seriatim to a die, a press plunger and a die mounted on said plunger, said die having means contained therein for (a) pressing the V ring of the assembly axially thereof, (b) squeezing the assembly of bars clrcumferentially intermediate their ends and, while said recited means are in operation, (c) spreading outwardly the terminus of the mounting sleeve of the assembly into tight engagement with the said V ring, said means arranged to act on the commutator assembly upon a single operation of the press plunger, said contained means comprising a plurality of slidable elements having compressible elements opposing their movement on work engaging movement of said die.

3. A press for commutator assemblies comprising an indexing table having thereon a series of supports for commutator assemblies and movable to present said supports seriatim to a die, a press plunger, and a die mounted on said plunger, said die having means contained therein for (a) pressing the commutator bars of the v assembly lengthwise, (b) squeezing the assembly of bars circumferentia'lly intermediate their ends and, while said recited means are in operation, (a). spreading outwardly the terminus of the mounting sleeve of the assembly into tight engagement with the said V ring, said means arranged to act on the commutator assembly upon a, Single operation of the press plunger, said contained means comprising a plurality of slidable elements having compressible elements opposing their movement on work engaging movement of said die.

4. The combination of claim 1 in which said die includes compression springs arranged in series to oppose the movement of the means (a), (b) and (c).

5. The combination of claim 2 in which said die includes compression springs arranged in series to oppose the movement of the means (a) and (b).

6. The combination of claim 3 in which said die includes compression springs arranged in series to oppose the movement of the means (a) and (b).

7. A die for completing a commutator assembly comprising a plurality of longitudinally extending commutator bars, said die comprising: a body portion; elements slidable within the body portion for substantially simultaneously squeezing the bars of said commutator assembly circumferentially intermediate their ends, and 1011- gitudinally; additional means sliding Within the body portion for applyin an axial pressure to the assembly; a series of compressible elements in the body opposing movement of both of said slidable elements, said die being arranged so that the noted slidable elements are applied seriatim to the commutator assembly; and means operating centrally on the assembly for spreading the retaining sleeve thereof.

8. The combination of claim 7 and means in the body for adjusting the compressibility of said compressible elements.

9. The combination of claim 7 in which the compressible elements in the body are compression springs, and means on the body for adjusting the compression of said springs.

10. A commutator assembly device for squeezing a commutator assembly circumferentially and holding it while the retaining sleeve of the assembly is spread to lock the assembly together, comprising a die body, and series of jaw elements arranged therein in a circumferential series as squeezing members, an element sliding in the die body having compression springs opposing its movement, and, means within the sliding element for engaging the jaw elements to move them toward each other, said jaw elements having means for abutting the commutator assembly.

11. The combination of claim 10 in which the jaw elements and the means within the sliding element are demountably held within the sliding element.

12. The combination of claim 10 in which the jaw elements and the means within the sliding element are arranged to be held in place in the sliding element by a retaining ring, and a retaining ring mounted on the working end of the sliding element.

13. The combination of claim 10, in which the said body has mounted thereon a threaded ring, said threaded ring having means thereon for applying compression to the said spring depending upon its theaded position on the body.

14. A commutator assembly device for squeezing a commutator assembly circumferentially and holding it while the retaining sleeve of the assembly is spread to lock the assembly together, comprising a. die body, and a series of jaw elements arranged therein in a circumferential series as squeezing members, an element slidable in the die body having compression springs opposing its movement, and means within the slidable element for engaging the jaw elements to move them toward each other upon work engaging movement of the die body, means in the die for engaging the commutator assembly axially, and means engaging the said jaw elements which means abuts on the jaw elements axially.

15. A die for the purpose described comprising a body portion, an outer annular series of compression springs in said body, means on the body for adjusting the compression on said springs, an inner annular series of springs in said body, means in the body for adjusting the compression on said inner series of springs, an outer sliding element and an inner sliding element in said body each being subject to said springs respectively, means associated with the inner sliding element to engage a commutator axially and means associated with the outer sliding body to engage a commutator assembly circumferentially, said inner element being held in place by the outer element, and removable means on the body for holding said outer element in place in the body, whereby said two elements can be replaced by merely removing said removable means.

16. The combination of claim 15 in which the removable means comprises a retaining ring secured to the open end of said body and against which the outer sliding element abuts.

17. In a die for the purpose described a device for squeezing the assembly of a commutator about the retaining sleeve thereof, comprising a body, a sliding element in said body, abutment means within said sliding element, a series of jaws arranged in circumferential series located within said sliding element, means engaging the jaws and arranged to abut against the end of a commutator assembly, and resilient means for expanding said jaws with reference to the axis of the series, said jaws having surfaces arranged to engage the periphery of the commutator assembly and tapered portions to engage the said abutments, and means within the body resiliently resisting the sliding of the sliding element.

18. The combination of claim 11, in which said series of jaws are held in place in the sliding element by a retaining ring mounted around an opening provided in the sliding element and into which opening the jaws project.

19. The combination set forth in claim 11 together with a, plunger located within the body and operating along the axis of the jaw assembly, so arranged as to engage and spread the end of said retaining sleeve when the jaws have been contracted by engagement of the tapered 45 1,300,567

portions with the abutments as resisted by the resilient resistance of the sliding element,

20. The combination of claim 11 together with a plunger located within the body and operating along the axis of the jaw assembly, so arranged as to engage and spread the end of said retaining sleeve when the jaws have been contracted by engagement of the tapered portions with the abutments as resisted by the resilient resistance of the sliding element, and a second sliding ele ment within said body, having means for resiliently resisting its sliding movement, said second sliding element being arranged to engage the as-' sembly of the commutator axially and initially and hold it while the jaws are contracted against the resilient resistance of the sliding element first mentioned.

21. A commutator assembly device for squeezing a commutator assembly circumferentially and holding it While the retaining sleeve of the assembly is spread to lock the assembly together, comprising a die body, a plurality of elements circumferentially arranged therein as squeezing members, an element slidable in the die body having resilient means opposing its movement, means within the slidable element for engaging said plurality of elements to move them toward each other upon work engaging movement of the die body, additional means engaging said plurality of elements to resist axial movement thereof, and means in the die for engaging the retaining sleeve axially and spreading it.

22. The device of claim 21 in which said additional means is mounted on said plurality of elements and engages said assembly axially upon work engaging movement of the die body.

JOSEPH W. DOLAN.

REFERENCES CKTED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,664,527 Poole Apr. 3, 1928 Poole Apr. 14, 1931 2,346,996 Poole 1, 1 Apr, 18, 1944 

